package cn.com.tpUtil;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.SecureRandom;

public class AES {

	/**
	 * 加密
	 * @param content 待加密内容
	 * @return
	 */
	public static String encrypt(String content) {
		return encrypt(content, PropertiesUtil.getProp("aes_key"));
	}
	
	/**
	 * 解密
	 * @param content 待解密内容
	 * @return
	 */
	public static String decrypt(String content) {
		return decrypt(content, PropertiesUtil.getProp("aes_key"));
	}
	/**
	 * 加密
	 * 
	 * @param content
	 *            待加密内容
	 * @param key
	 *            加密的密钥
	 * @return
	 */
	public static String encrypt(String content, String key) {
		try {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			
			SecureRandom random=SecureRandom.getInstance("SHA1PRNG");
			random.setSeed(key.getBytes());
			
			kgen.init(128, random);
			SecretKey secretKey = kgen.generateKey();
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
			byte[] byteContent = content.getBytes("utf-8");
			cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
			byte[] byteRresult = cipher.doFinal(byteContent);
			StringBuffer sb = new StringBuffer();
			for (int i = 0; i < byteRresult.length; i++) {
				String hex = Integer.toHexString(byteRresult[i] & 0xFF);
				if (hex.length() == 1) {
					hex = '0' + hex;
				}
				sb.append(hex.toUpperCase());
			}
			return sb.toString();
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 解密
	 * 
	 * @param content
	 *            待解密内容
	 * @param key
	 *            解密的密钥
	 * @return
	 */
	public static String decrypt(String content, String key) {
		if (content.length() < 1)
			return null;
		byte[] byteRresult = new byte[content.length() / 2];
		for (int i = 0; i < content.length() / 2; i++) {
			int high = Integer
					.parseInt(content.substring(i * 2, i * 2 + 1), 16);
			int low = Integer.parseInt(content.substring(i * 2 + 1, i * 2 + 2),
					16);
			byteRresult[i] = (byte) (high * 16 + low);
		}
		try {
			KeyGenerator kgen = KeyGenerator.getInstance("AES");
			
			SecureRandom random=SecureRandom.getInstance("SHA1PRNG");
			random.setSeed(key.getBytes());
			
			kgen.init(128, random);
			SecretKey secretKey = kgen.generateKey();
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec secretKeySpec = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
			cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
			byte[] result = cipher.doFinal(byteRresult);
			return new String(result);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
}
